Understanding the complex mechanisms of viral oncogenesis requires a broad understanding in at least three areas of research: virology, molecular and cellular biology, and immunology. It is the goal of the proposed training program to provide graduate students and postdoctoral fellows a challenging and supportive scientific environment in which both formal and informal training occurs within these three broad, but interrelated areas. The breadth of the scientific interests of the training faculty create a blend of research areas, many of which incorporate virus systems to dissect the molecular events that occur within the normal vs. the cancer cell. The specific research programs include (a) molecular and cellular biology: regulation of cell growth and gene expression, oncogenes, cell signaling, and mechanisms of neoplastic transformation;(b) immunology: antigen processing, viral and tumor immunology, and the role of endocrine factors on the cellular immune response;and (c) virology: molecular studies of virus replication assembly, oncogenesis, pathogenesis, and gene regulation using virus systems that include adenoviruses, hepatitis viruses, herpes simplex viruses, papillomaviruses, polyomaviruses, and retroviruses. The trainers associated with the proposed training grant have their primary academic appointments within either the Departments of Microbiology and Immunology, Medicine, Pathology, or Pediatrics. Each of the trainers directs productive and well-funded research programs and has a strong commitment towards the training of young scientists. Nearly 50% of the research funding that supports the research programs of the trainers is from the National Cancer Institute of the National Institutes of Health. Each of the trainers is associated with multiple interdisciplinary graduate programs that cross departmental and college boundaries. A major new development at the Penn State College of Medicine is the recent establishment of the Penn State Cancer Institute. The establishment of the Cancer Institute has enhanced the training environment for young scientists interested in cancer. The training program for graduate students and postdoctoral fellows includes a dynamic research environment that has excellent research and core support facilities and well-equipped faculty research laboratories. The research training environment is further enhanced by interactions among the research programs as well as numerous seminars, journal clubs and symposia and special experiences that enhance the cancer training environment. The proposed training program provides a comprehensive training experience for trainees who are interested in a career in the area of virus and cancer research.